Gets completion candidates for a full command line and a cursor position within it.
public IEnumerable<string> GetCompletionsForLine(string commandLine, int cursorPosition, string? commandName = null)
The full command line as typed in the shell, typically including the executable name.
The 0-based cursor position within commandLine.
The invocation name (e.g. "mytool") to strip from the beginning of the token stream.